How can mutant genes contribute to congenital malformations?

Mutant genes contribute to congenital malformations by disrupting the normal development of an organism, often by interfering with the synthesis or function of critical proteins. A gene is a sequence of DNA that directs the production of proteins, which are essential for all cellular functions. When a mutation alters this sequence, it can lead to the production of a defective protein, the synthesis of an abnormal protein, or the complete absence of a protein.123

These genetic errors impact development in several ways:

• Loss of Function: Mutations such as nonsense or frameshift mutations can cause a total loss of protein function, which may be fatal or result in severe developmental defects if the protein is a key enzyme in metabolism.23
• Regulatory Interference: Mutations in regulatory regions can inhibit protein production or cause it to occur at inappropriate times, disrupting the precise timing required for embryonic development.3
• Inheritance Patterns: Mutant alleles can be passed from parents to offspring in dominant or recessive patterns, or they may arise sporadically as new mutations in germ cells.42
• Somatic Mutations: Mutations occurring in somatic cells after conception can also lead to malformations, as these cells are responsible for building the tissues of the developing fetus.25